Clean Line Energy Partners

The existing transmission system was created primarily as a result of local utility planning to connect population centers with nearby fossil fuel power plants; it is now insufficient to meet the demands of our new energy economy. We need long-haul HVDC transmission lines to move America’s vast renewable energy resources to market.  Clean Line Energy is developing new infrastructure projects that will connect the best renewable energy resources in North America to communities and cities that lack access to new, low-cost renewable power. 

Why HVDC?

Direct current (DC) is the preferred technology for moving large amounts of power across long distances. There are many advantages for using DC over an equivalently sized alternating current system (AC): Over long distances, DC transmission can move more power with less electrical losses; higher efficiency means a lower transmission cost, helping renewable energy compete against other power sources; HVDC can enhance system stability, allow the operator complete control over power flow, and facilitate the integration of wind from different resource areas; and DC transmission lines require narrower right-of-way footprints.

Historically, the transfer of electricity between regions of the U.S. has been over high voltage AC transmission lines, which means that both the voltage and the current on these lines move in a wave-like pattern along the lines and are continually changing direction. In North America, this change in direction occurs 60 times per second (defined as 60 hertz [Hz]). The electric power transmitted over AC transmission lines is exactly the same as the power we use every day from AC outlets, but at a much higher voltage.